Seed Size Classes Research Articles

Effects of seed size and maturity on the growth and yield of faba bean (Vicia faba L.)

The importance of seed size and flowering time to yield in faba bean has not been well defined for many of the faba bean growing areas of southern Australia. The objective of this work was to examine the relative importance of these traits to yield of dryland faba bean at 2 sites in South Australia. Grain yield, seed growth rate, the partitioning of dry matter to the seed, and water use efficiency for dry matter production and yield of faba bean cultivars differing in seed size and maturity were measured. Early-, intermediate-, and late-flowering accessions in each of 3 seed size classes, large (>1200 mg/seed), medium (800-1200 mg), and small (<800 mg), were grown at the Waite Institute (623 mm average annual rainfall) and Charlick Experiment Station (509 mm). A small-seeded and intermediate flowering cultivar, Fiord, which is well adapted in South Australia was also included. Dry matter production and grain yields at the Waite Institute were higher than at Charlick and the difference tended to be greater in the large-seeded accessions. Average yields at the 2 sites were about 400 g/m 2 and were not consistently related to seed size, although the highest yielding accession at both sites was large-seeded. Among the small- and medium-sized seed accessions, the early-flowering accession yielded more than late-flowering accessions, but among the large-seeded accessions there was no relationship between flowering time and yield. Although there were significant differences between accessions and sites in individual yield components, yield was not significantly correlated with any particular component. There was strong compensation between seed number and seed size and high yields were obtained from a range of seed sizes. In contrast there was a positive relationship between dry matter production and yield. Partitioning of dry matter during pod filling and harvest index differed little between genotypes. Yield was therefore related to biomass accumulation, and whether this was partitioned between a small number of large seeds or a large number of small seeds was not an important factor.

Seed size effects on growth and N 2 fixation of juvenile sainfoin

Seed size of forage legumes influences seedling establishment and vigor. Two studies were conducted to examine the effects of seed size on growth and N 2 fixation of juvenile sainfoin ( Onobrychis viciifolia Scop.). In two growth chamber experiments, ‘Remont’ sainfoin was evaluated for nodulation, plant height, dry matter yield, N concentration, and acetylene reduction activity (ARA). Seedlings from large seed emerged faster, had more nodules, and had higher N 2 fixation rates at most harvest dates up to 84 d. Across all harvests, seed size accounted for 60, 81, 87, 90, and 98% of the variability in mean ARA, nodule number, total plant N content, plant dry weight, and plant height, respectively. The superiority of seedlings from large seed was not due to increased relative growth rates. Two Remont seed lots that differed in seed weight distributions had similar ARA and shoot dry weight patterns, but varied in their correlations between ARA and seed size. It appears that the factors influencing seed size also affected subsequent seedling behavior of these two seed lots. Divergent individual plant selections for high or low ARA at 56, 70, or 84 d would have arisen from the largest or smallest seed size classes, respectively, if seed size effects had been ignored in a breeding program. Considerable variability for plant dry weight and ARA existed within seedlings from uniformly sized seed. We conclude that for breeding purposes, growth or ARA analyses of juvenile sainfoin should be conducted with sized seed in order to minimize seed-size effects and to better expose genetic variability in N 2 fixation.

Morphological Relationships Among Coexisting Heteromyids: An Incisive Dental Character

We studied morphological relationships among coexisting heteromyid rodents from two North American deserts. Because limb morphology affects foraging behavior, we divided species into bipedal and quadrupedal guilds. The trait for which interspecific size ratios tended most toward equality both within each guild and among combined guilds is the width (cutting edge) of the upper incisor. Sizes of this trait were interspersed regularly between bipedal and quadrupedal guild members. Size ratios for pouch volume tended toward equality among Great Basin heteromyids both within each guild and among combined guilds. For no other traits did size ratios approach equality. Incisors of heteromyids are used for husking, some of which occurs above ground where predation risk is high. Therefore, husking speed may be critical. For each species there may be an optimal size for a seed that is too large to be pouched unhusked but that can be husked efficiently enough to outweigh the predation risk, and this seed size class may be the object of evolutionary specialization. A strong correlation between pouch volume and incisor width supports this hypothesis. Specializing on different seed sizes may result from competition.

Relationships among seed weight components, seedling growth traits, and predicted field breeding values in slash pine

Dry weights of seed components (seed coat, gametophyte, and embryo), germination vigor (peak value and days to 50% germination), and three seedling growth traits (total height, stem dry weight, and shoot dry weight) under regimes of low (5 ppm) and high (50 ppm) nitrogen were measured for 64 open-pollinated families of slash pine (Pinuselliottii Engelm.) that have been field tested for 5- and 15-year volume growth. There were moderate to strong relationships among the seed components using the 64 family means (r = 0.80 between gametophyte weight and embryo weight; r = 0.68 between seed-coat weight and embryo weight; r = 0.50 between seed-coat weight and gametophyte weight). Seed-coat, gametophyte, and embryo weight, expressed as a percentage of total seed weight, were approximately 44, 50, and 6%, respectively, and those percentages were similar for small, medium, and large seed size classes. Family mean correlations between seed weight components and seedling growth traits were generally high at 12 weeks and decreased at 24 and 40 weeks, depending on the trait; however, most correlations remained statistically significant throughout the 80-week measurement. Correlations between seed components and seedling traits were generally higher in the high-N regime at 12 weeks, but by the 40- or 80-week measurements, correlations were generally higher in the low-N regime. Among the seed weight components, embryo weight consistently had the strongest relationship with seedling growth traits. Family mean correlations between germination vigor indices and seedling growth traits were high at 12 weeks, but declined significantly thereafter. Correlations between seed weight components and predicted field breeding values for 5- and 15-year volume growth were significantly greater than zero, and indicated that embryo weight in particular may be useful in genetic selection for volume growth. Owing to the strong relationship between seed weight components and shoot growth throughout the second growing season and beyond, statistical adjustments for seed weight effects in slash pine might remove useful genetic variation.

EFFECTS OF SEED SIZE ON LIMA BEAN GROWTH AND DEVELOPMENT

Objectives of this study were to determine the effects of lima bean seed size differences and a short chilling period after planting on seedling emergence rate, seedling abnormalities and vigor. Individual seeds of 'Jackson Wonder' lima bean were weighed and placed into one of five size classes: 24-33. 36-41. 44-49, 52-57, and 60-73 g per 100 seed. Seed of each size class were germinated at a constant 23-26C or chilled at 8C for 24 hrs and then moved to 23-26C conditions for the remainder of the study. A 24 hr chilling period after planting had a detrimental effect on subsequent lima bean seedling emergence only from 8 through 11 days after planting. Plant fresh and dry weights were significantly less for the chilled seed treatment. Temperature treatments had no effect on percent normal and abnormal seedlings or primary leaf area. No differences in seedling emergence number or rate were found among seed size classes. Smaller seedclasses had significantly fewer normal and more abnormal seedlings than larger seed size classes. The largest seed class produced seedlings with about two times more fresh and dry weights and leaf area than those from the smallest seed weight class. Plant fresh and dry weights and leaf areas from all seed size classes were significantly different from each other.

Seed Size and Planting Depth Effects on Emergence and Yield of Pinto Bean

Seed size and planting depth affect plant performance of many crop species. Growers claim that large pinto bean (Phaseolus vulgaris L.) seeds emerge faster and produce higher seed yields than small seeds. A study was conducted during 1986 and 1987 on Billings silty clay loam soil (fine-silty, mixed [calcareous], mesic Typic Torrifluvents) at the Colorado State University Fruita Research Center to investigate the effects of seed size class (small, medium, and large), representing 30, 40, and 30% of the original bulk sample by weight, respectively, and a check; and planting depth (1-, 2-, and 3-in.) and their interaction on seedling emergence and yield of pinto bean. No seed size × planting depth interactions occurred. Seed size effects varied. Seedling emergence of small seeds in 1987 was greater than large and medium seeds. The plant stand from small seeds in 1986 was lower than large and check seeds. Plants grown from large and medium seeds yielded more than small seeds in 1986. Planting seeds at a 3-in. depth slowed seedling emergence and reduced plant stand both years, and lowered yield in 1987. These data suggest that an uneconomical, high cleanout percentage during seed conditioning would be necessary to obtain large seeds and the improved performance of large seeds would not be predictably advantageous. Currently recommended commercial seed conditioning practices to size pinto bean seed lots are probably adequate.

Seed Size and Plant Growth Form as Factors in Dispersal Spectra

All vascular plant species were listed on eight sites near Sydney, Australia. Four sites were on infertile and four on fertile soil. Each of the 355 species was classified according to seed mass (measured as fresh mass of embryo plus endosperm), morphological adaptations for dispersal by different vectors, and growth form. The infertile—soil sites had more species and more cover adapted for dispersal by ants, and the fertile—soil sites had more species and more cover with fleshy fruits adapted for dispersal by vertebrates. We tested the hypothesis that this difference could be interpreted as a secondary correlate of seed size or of growth form. Species with smaller seed mass of growing to <2 m tall were significantly more likely to be adapted for dispersal by ants relative to vertebrates. An indirect association via growth form was capable of accounting for up to 84% of the relationship between soil type and dispersal mode, and indirect association via seed mass for up to 23% of the relationship; the two together could account for a maximum of 85%. The indirect association association via seed mass relatively weaker because seed masses proved not to be very different between these soil types. There remained a significant residual tendency for species in any given seed size class and growth form to be more likely to be dispersed by vertebrates relative to ants on fertile soils than on infertile soils.

Characterization of the negative association between seed yield and seed size among genotypes of common bean

Contrary to expectations from arguments of exponential growth or limiting factors, seed yield and seed size of different bush-bean (Phaseolus vulgaris L.) genotypes are frequently negatively associated. Four sets of yield data are analyzed to characterize this apparent seed size limit to yield potential. Comparisons of 57 genotypes, classified as small-seeded vs. medium-to-large-seeded and grown in three trials at two locations in Columbia, gave mean yields of 2190 and 1740 kg ha−1 for the respective seed-size classes, corresponding to a 280 kg ha−1 reduction in yield per 100 mg increase in cultivar seed weight. Published data for a trial conducted at five sites with 190 genotypes, for 19 experiments of an international yield trial, and for 42 nurseries conducted in Michigan, confirmed this relation, but also showed that positive relations between seed size and yield occur in certain environments. Including effects of length of growth-cycle did not eliminate overall negative relationships. Possible causes of the seed-size effect include effects of characteristics correlated with seed size that in turn affect efficiency of certain physiological processes, or differences in adaptation resulting from limited gene exchange among gene pools differing in characteristic seed size. To examine the possibility of a physiological cause related to developmental correlations between seed size and tissue cell volumes, seed weight and approximate cell volumes of cotyledons, hypocotyl and root endodermis, guard cells, and palisade mesophyll, and volumes of pollen grains, were determined for 15 genotypes, including two wild accessions. All volume measurement had positive correlations with seed weight except for palisade mesophyll. Principal-components analysis of cell volumes defined a first component accounting for 51% of total variance, and which had a correlation of r = − 0.91 (P < 0.01) with seed weight. Further comparison of seed weightand pollen grain volume in 33 genotypes gave a correlation of r = 0.67 (P < 0.01).

Variability for Seed Size and Yield in Two Tall Dropseed Populations

Tall dropsecd [Sporobofusclsper(Michx.) Kunth var. asper] is a drought-tolerant, perennial, warm-season grass that has potential for forage and soil conservation purposes. A prairie and an adjacent roadside population from northeastern South Dakota were evaluated for seed yield and size characteristics for 3 years (1985-1987) in a spacoplant nursery at Brookings, S.Dak. The objective was to obtain information on between and within population variability and intraphmt variability that would provide a basis for designing a breeding program to improve seed production and quality in this germplasm. The roadside population produced significantly (PCO.01) higher seed yields and larger mean 100~seed weight than the prairie population. Percent small seed (based on screen-separation of seed yields of individual plants into small, medium, and large seed size classes) decreased significantly (p<O.Ol) as seed yield increased, but the volume of small seed increased concurrently with seed yield. Percent large seed increased significantly (P<O.Ol) with increased seed yield and mean seed size. Highly significant (P-CO.01) differences were found among years for seed yield and mean seed size, but all plants produced seeds of each size class each year. Interand intrapopulation genetic variability was indicated for yield of the large seed size class. Screen-separation of individual plant seed yields could be used to identify superior genotypes to be used in the development of a cultivrr that produces a high percentage of large seed.

Mechanical Mass Selection Methods for Improvement of Oat Groat Percentage

Three methods of mechanical mass selection for seed density, aspiration (ASP), gravity table selection (GT), and gravity table selection with a seed polishing pretreatment (P‐GT), were evaluated and compared for effectiveness of increasing caryopsis (groat) percentage and test weight in oat (Avena sativa L.). Selection using these methods in two heterogeneous F5 populations resulted in absolute differences in the groat percentage between high and low density treatments of 0.3 and 0.5% for ASP and P‐GT, respectively. The GT selection resulted in a lower groat percentage in the high‐density treatment. Selection methods interacted with populations and seed size classes. These interactions were due to different levels of variation in the populations for seed size and shape. Two cycles of selection for high groat percentage beginning in F3 segregating bulk populations showed little overall improvement. Selection increased the number of fertile florets per spikelet. This increase in fertility was due primarily to a 22% increase in tertiary florets per panicle per cycle of selection. Tertiary floret number exhibited a negative genotypic correlation with groat percentage, which limited improvement for groat percentage. There also were significant changes in plant height, days to flowering, and harvest index in these experiments with direction and magnitude dependent on the individual population. Effectiveness of mechanical mass selection for groat percentage could be increased by avoiding selection for characters such as tertiary kernels which have undesirable correlated effects on milling quality.

Soybean Seed Size Influences Expression of the Impermeable Seed‐Coat Trait1

Soybean [Glycine max (L.) Merr.] seeds with the impermeable seed‐coat trait have been shown to retain quality better than typically, permeable seeds. Impermeable seeds, however, become permeable and imbibe water after different periods of soaking even when seeds are from the same genotype or plant. These differences in response demonstrate variation in the expression of this character. The purpose of this study was to determine if seed size was associated with the variation in expression within soybean breeding lines. Seeds of nine lines were grown in each of 2 yrs and separated into three size classes based on seed diameter. Seed permeability was determined for each size class by soaking seeds in water for 2, 4, 8, 24, and 72 h. Smaller seeds exhibited the impermeable response at a higher frequency than larger seeds after each soak in both years. Differences in seed permeability among size classes increased as soaking time increased. When data were averaged over years and lines, each decrease in seed size class was associated with a 17% increase in impermeable seed expression, after a 72 h soak. Although there were significant differences among lines in impermeable seed percentage, seeds within all lines exhibited a negative relationship between size and impermeable seed expression in at least 1 of 2 yrs, seven lines exhibited this relationship in both years. Results obtained indicate that variation in the impermeable response of seeds within an impermeable‐seed line is associated with seed size. Smaller seeds expressed the impermeable response in a higher frequency than larger seeds.

Tetrazolium Chloride Test for Spring Wheat Seedling Vigor at Low Temperatures 1

Low soil temperature is a major environmental factor limiting seedling establishment of early sown spring wheat [Triticum aestivum (L.)]. This laboratory study was conducted to determine if a red pigment, formazan, extracted from tetrazolium chloride (TZ)-treated embryos could be used as a rapid quantitative test to screen spring wheat cultivars for low temperature seedling vigor. The effects of several factors were considered in developing the screening technique. These were seed size, sample size, length and temperature of the imbibition period, and the correlation of formazan optical density (OD) values with vigor. Seeds of different size categories were imbibed for various time periods at test temperatures (5, 7, or 10°C) prior to the addition of TZ. Formazan was then extracted and OD readings were obtained. Vigor was estimated by measuring shoot length after growth in the dark for 20 days at 10°C or 31 days at 5°C in a water culture medium. Seedling dry weight was also taken after 20 days growth at 10°C. Test results showed that differences among the genotypes for seedling vigor were correlated with formazan OD values. The larger the seed size class the greater the TZ reduction ability. Either five or 10 seeds per genotype were shown to give good genotype separation with low coefficients of variability. Genotypic differences in TZ reduction were apparent after 4 or 5 days imbibition at 5°C or 2 or 3 days imbibition at 10°C. At 7°C, genotypic differences in TZ reduction were apparent at 3, 4, or 5 days. A 4-day imbibition period at 7°C appeared to. offer the greatest efficiency for genotypic screening. The test promises to be a simple, comparatively rapid, and reliable method for screening wheat genotypes for low temperature seedling vigor.

Influence of seed size on germination and early development of loblolly pine (Pinustaeda L.) germinants

Seed size was examined as a possible explanation for variation in the size of containerized loblolly pine (Pinustaeda L.) seedlings. Under laboratory conditions of minimal environmental stress, larger seed were found to germinate more quickly and produce a larger germinant after 28 days of growth. In a similar experiment conducted under greenhouse growing conditions, large seed produced the largest seedlings. Size differences among seedlings in both experiments resulted from differences in the rate of germination unique to each seed size class. Consequently, seedling size and possibly uniformity of growth were considered to be a function of germination patterns which were strongly influenced by seed size and weight.

Influence of Seed Size on Seed Quality of Sorghum

Five seed size classes of sorghum CSH 5 hybrid and its parents, CS 3541, ms 2077 A and 2077 8 were studied for the relative differences in seed quality. The 1000-seed weight, seed volume and specific gravity of seeds showed distinct and significant differences among seed sizes. The germination and field emergence potential of 10, 9 and 8 retained seeds were significantly higher than those from 7 and 5 retained seeds. The seedling vigour ass- essed by seedling growth measurements and dry matter estimation in plant parts and the vigour index values amply showed the superiority of the large and medium size seeds over the smaller ones. The study had revealed that the optimum sieve size is 8/64" round per- forated metal sieve for processing the seed lots of sorghum CSH 5 hybrid and its parental lines.

Frequency of euploids in different seed size classes of hexaploid triticale

Bulk seeds of each of nine strains of hexaploid triticale were classified according to size by passing them over four round-holed sieves, 8/64, 9/64, 10/64 and 11/64-inch mesh. The actual size was different in different strains depending on the characteristic seed size of the strain (Table 2). Of the nine strains, six had low aneuploid frequency (11.8% average) and three had high aneuploid frequency (39.0% average) in the bulk populations. Chromosome numbers were counted in root-tip mitosis of germinating seeds.

Relationship of Seedling Vigor to Respiration and Tetrazolium Chloride Reduction by Germinating Wheat Seeds1

AbstractThe effects of age and size of seed on seedling vigor, rate of respiration, and 2,3,5‐triphenyl‐2H‐tetrazolium chloride (TTC) reduction by germinating seeds were studied in the laboratory. Wheat seed (Triticum aestivum ssp. compactum (Host) MacKey ‘Elmar’) was used. Stratification was necessary to eliminate the effect of dormancy in the youngest seed class. Significant positive correlations were found between rate of emergence and vigor (ability to emerge from deep seeding), emergence and rate of respiration, and between vigor and both tetrazolium reduction and rate of respiration for seed of different ages.With different seed size classes, significant positive correlations were found between seed weight and tetrazolium reduction, and between shoot weight per plot and tetrazolium reduction.In a preliminary test, varietal differences in seedling vigor, which were largely due to relative coleoptile elongation, were not correlated with TTC reduction. The possible place of TTC reduction as an empirical seedling vigor test and respiration of germinating seeds as a component of vigor are discussed.

THE EFFECT OF SEED SIZE ON GERMINATION, SURVIVAL AND INITIAL GROWTH IN WHITE SPRUCE

A 50 gram sample of white spruce seed of regular nursery production quality was divided into three size classes, (a) small, &lt;1.41 mm, (b) medium, 1.41-1.59 mm, (c) large &gt;1.59 mm. Laboratory tests were conducted with 2,000 seeds of each size class in a 2:1, sand: peat soil mixture.The differences in total germination and in the first year's survival rates, between the three seed size classes were found to be not statistically significant. The difference in the height and weight of the seedlings, after one season's growth, small, 19.0 mm and 5.8 mg., medium, 21.7 mm and 7.7 mg., large, 24.9 mm and 9.8 mg., were found to be highly significant.From the results of this test it is concluded that the larger the white spruce seed the larger will be the resultant seedling after the first season's growth, but seed size affects neither the germination nor the survival rate in this species.

Differential Incidence of Loose Smut Among Seed‐Size Classes Within Barley Seedlots1

Crop ScienceVolume 2, Issue 2 cropsci1962.0011183X000200020025x p. 162-164 Article Differential Incidence of Loose Smut Among Seed-Size Classes Within Barley Seedlots1 Karl D. Fezer, Karl D. Fezer Assistant Professor, Department of Plant Pathology and Botany, University of Minnesota.Search for more papers by this author Karl D. Fezer, Karl D. Fezer Assistant Professor, Department of Plant Pathology and Botany, University of Minnesota.Search for more papers by this author First published: 01 March 1962 https://doi.org/10.2135/cropsci1962.0011183X000200020025xCitations: 1 1 Paper No. 4653, Scientific Journal Series, Minnesota Agricultural Experiment Station, St. Paul, Minnesota. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume2, Issue2March–April 1962Pages 162-164 RelatedInformation